5hgk
HIV-1 CA N-terminal domain, open conformationHIV-1 CA N-terminal domain, open conformation
Structural highlights
FunctionPublication Abstract from PubMedDuring the early stages of infection, the HIV-1 capsid protects viral components from cytosolic sensors and nucleases such as cGAS and TREX, respectively, while allowing access to nucleotides for efficient reverse transcription. Here we show that each capsid hexamer has a size-selective pore bound by a ring of six arginine residues and a 'molecular iris' formed by the amino-terminal beta-hairpin. The arginine ring creates a strongly positively charged channel that recruits the four nucleotides with on-rates that approach diffusion limits. Progressive removal of pore arginines results in a dose-dependent and concomitant decrease in nucleotide affinity, reverse transcription and infectivity. This positively charged channel is universally conserved in lentiviral capsids despite the fact that it is strongly destabilizing without nucleotides to counteract charge repulsion. We also describe a channel inhibitor, hexacarboxybenzene, which competes for nucleotide binding and efficiently blocks encapsidated reverse transcription, demonstrating the tractability of the pore as a novel drug target. HIV-1 uses dynamic capsid pores to import nucleotides and fuel encapsidated DNA synthesis.,Jacques DA, McEwan WA, Hilditch L, Price AJ, Towers GJ, James LC Nature. 2016 Aug 18;536(7616):349-53. PMID:27509857[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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